There is an installer for the RunInUAE in the archive to get things up and running. It erroneously prompted for an Amiga Appz: assign which I mounted to the extracted archive folder and the install then proceeded as normal.

Here is the readme for the new RunInUAE Beta which explains the addition of the new UAE JIT Beta 5:

Here is the resulting Emulation Folder after installation, which includes the new E-UAE JIT Beta folder and my custom Emulation folders I created a long time ago (explained on my blog here) for running Amiga 1200, 2000 and A4000 systems.

I renamed the older UAE and copied the updated UAE program to the Amiga 4000D folder so it used the new JIT version when running my customised emulations (not just the default RunInUAE functionality):

I then added the new JIT config sections from the installed RunInUAE Beta 3 files to my custom A4000D emulation config .uaerc file to get it to use the new Beta:

Demo time! I ran the A4000D Amiga emulation to try out the AGA demos. You can run this in a window but full screen is much nicer in my opinion.

Some screenshots of other demos running well - TBL's Starstruck (above/below):